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| 疏浚淤泥固化土宏微观孔隙结构特征及其对渗透性影响 |
| MACRO AND MICRO PORE STRUCTURE CHARACTERISTICS ITS EFFECT ON PERMEABILITY OF DREDGED SILT SOLIDIFIED SOIL |
| 投稿时间：2017-12-27 修订日期：2018-03-08 |
| DOI： |
| 中文关键词: 固化土 有效孔隙度 压汞试验 渗透率 孔隙结构 毛细模型 |
| 英文关键词: solidified soil effective porosity MIP permeability pore structure capillary model |
| 基金项目: |
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| 中文摘要: |
| 采用压汞试验、渗透率试验和孔隙度等试验方法，研究疏浚淤泥固化土的孔隙度、微观孔隙结构特征、渗流特征及其相互关系。压汞实验结果显示，各工况土样的孔隙频率分布函数均为典型的双峰曲线，存在两个集中的孔喉半径径区间：0.02um～0.04um和3um～30um；基于疏浚淤泥固化土水化反应生成致密水化产物这一机理和孔隙频率分布曲线，提出将疏浚淤泥固化土的孔隙直径进行分组，微孔组和中孔组处于峰值区间，微孔组的最可几孔径随着初始密度和龄期的增加逐渐增加，中孔组的最可几孔径随着初始密度和龄期的增加逐渐减少。另外，孔隙度和渗透实验结果显示，土样的有效孔隙度随龄期逐渐减小主要发生在固化28天前，28后土样有效孔隙度基本保持不变，而土样渗透系数仍在降低，在该阶段50%以上的中孔向小孔和微孔转化。因此，提出采用“有效孔隙度”作为表征土样的宏观孔隙特征参数，采用“孔径和体积频率值”作为表征细微观孔隙结构参数，并采用毛细模型建立宏微观孔隙结构参数和宏观渗透性之间的定量关系。 |
| 英文摘要: |
| The porosity, micro pore structure characteristics, permeability properties and the relationships between pore structure and permeability of dredged silt solidified soil (DSSS) were investigated by using MIP tests, permeability experiment and porosity test. The results of mercury intrusion porosimetry (MIP) tests show that the frequency distribution curve of pore volume of soil sample presents a typical bi-peak distribution, and the two concentrated pore throat radius intervals are:0.02um～0.04um and 3um～30um. The pore diameter of DSSS is divided into groups according to the compact structure of hydration reaction and the frequency distribution of pore volume of DSSS. In addition, the most possible aperture of the microporous group increases with the increase of initial density and curing age. The most possible aperture of the mesopore group decreases with the increase of initial density and curing age. Besides, the results of porosity test and permeability test show that the effective porosity of the DSSS gradually decreases with curing age during the first 28 days and the effective porosity remained unchanged after curing for 28 days. While, the permeability coefficient of DSSS still decreases after curing for 28 days, and over 50% of the mesopores at this stage are transformed into small pores and micropores. Hence, the "effective porosity" and “the pore size and volume frequency value” are proposed to present the characteristics of macroscopic and microscopic pore structure of DSSS, and a capillary model is used to correlate the permeability with macro and micro pore structure parameters. |
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